ENGLEWOOD, Colo. (AP) — As an 85,000-square-foot indoor practice facility rises in the background of the Denver Broncos' training complex, fourth-year safety Quinton Carter not so quietly goes about resurrecting his NFL career.

The two projects are intertwined.

Carter missed most of the last two seasons after getting hurt inside the team's rented practice bubble during a rainstorm two summers ago, blowing out a hamstring and a knee while avoiding a soccer goal after defending a deep pass from Peyton Manning to Eric Decker.

After starting 10 games as a rookie in 2011 and intercepting Ben Roethlisberger and Tom Brady in the playoffs, Carter needed microfracture surgery following his injury inside the practice bubble, which doesn't have regulation size fields like the new facilities will.

The Broncos thought so much of him that they kept him around on injured reserve for a second straight season last year rather than releasing him, and that trust is paying off this offseason as Carter has returned to form, providing depth for an already superb secondary.

Carter has been getting snaps at strong safety with the first-string nickel defense, and with free agent acquisition T.J. Ward limited by a tight hamstring the last two weeks, Carter has seen plenty of action in the base defense, as well.

"Quinton, having him back in the rotation, letting him get snaps and watching the way he is — instinctive and makes plays, plays with confidence — it'll be a great addition to have him back at full strength," defensive coordinator Jack Del Rio said.

The Broncos have several defensive players returning from injuries that sidelined them for the Super Bowl, including safety Rahim Moore, who cried when he put on a uniform this spring and returned to practice for the first time since November.

For Carter, it was doubly emotional.

"I've been out for two years," he said Monday as the Broncos began their final week of offseason practices. "Man, it seems like an eternity since I've played. So, I mean, I'm ecstatic to be out here. I sit out here and just take it all in."

Carter is cutting sharply and running smoothly, showing no signs of the injury.

Doubt, he said, was a constant companion during his time away from the football field, especially when he went home at night, away from the meeting room and the training table.

"I mean, I was thinking, 'Aw, geez' every day because it's easy to be forgotten in this league," Carter said.

Among the veterans who lifted his spirits was Hall of Famer Rod Woodson, who was a guest coaching instructor during the Broncos' minicamp.

He approached Carter and "just said, 'Don't get discouraged. You'll get back to exactly where you want to be,'" Carter said. "He said he played 14 years after his surgery. So, that was really helpful."

Also assuaging his fear was the knowledge that the Broncos hadn't given up on him.

"It means the world, especially in this business," Carter said. "They pretty much believed in me, so that gave me the confidence to just take my time, get healthy and now I'm ready to make a difference."

The hardest part of the last two years wasn't the strenuous rehab or missing games, he said, but "just staying optimistic, keeping my mind on that big goal of returning and making a difference on the team through all the ups and downs. By far that's the most difficult point but I'm here now, just taking it a day at a time, just getting better every day."

He continued hosting his offseason football camps for kids, which he started while still a member of the University of Oklahoma Sooners, where he admonished the youngsters to keep their heads up through adversity.

"It was easier for me to talk to them about obstacles and me actually going through one at the time," Carter said. "You've got to stay optimistic and work every day. (There were) a lot of days I thought I would never play again, but I'm blessed to be here."